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App Dev Worksheet: Variables, Lists and Saving

App development lesson 15: Data: variables, lists and saving · Set 161 · 40 questions
TalentJR

Developer's tip (Box, list, place): A variable holds one value; a list holds many in order. Positions start at 0. push adds to the end; pop takes off the last item; length is how many items. On the phone: works offline, private. In the cloud: shared, any device, needs the internet.

NameDateTime takenScore ___ / 40
  1. 1.💾 What does this code show? (Positions start at 0.)
    let notes = ["Art", "Hindi", "Music", "Sports"];
    show(notes[1]);     (a) Sports (b) Hindi (c) Art (d) Music
  2. 2.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Music", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Music (b) Hindi (c) Maths
  3. 3.💾 pop() takes off the last item. What does this code show?
    let notes = ["Maths", "Sports", "Hindi"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Hindi (b) Sports (c) Maths
  4. 4.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Monsoon", "Stars", "Ocean"];
    show(songs[1]);     (a) Kites (b) Ocean (c) Monsoon (d) Stars
  5. 5.💾 Which works with no internet at all? (a) a shared chat (b) a cloud leaderboard (c) a cloud backup (d) data saved on the phone
  6. 6.True or false: your last game level fits saving on the phone. (a) True (b) False
  7. 7.💾 What number does this code show?
    let songs = ["Sunrise", "Rain", "Kites", "Ocean"];
    songs.push("Stars");
    show(songs.length);
  8. 8.💾 What number does this code show?
    let points = 5;
    points = points - 4;
    points = points + 2;
    show(points);
  9. 9.💾 Where should the app save photos on two devices: on the phone or in the cloud? (a) on the phone (b) in the cloud
  10. 10.Which of these fits saving on the phone? (a) a class leaderboard (b) notes to read offline (c) chat messages to friends (d) photos on two devices
  11. 11.💾 Where should the app save a class leaderboard: on the phone or in the cloud? (a) on the phone (b) in the cloud
  12. 12.💾 What number does this code show?
    let friends = ["Kabir", "Aman"];
    friends.push("Meera");
    show(friends.length);
  13. 13.💾 Which can hold many values in order? (a) a switch (b) a button (c) a list (d) a single number
  14. 14.💾 Where should the app save chat messages to friends: on the phone or in the cloud? (a) in the cloud (b) on the phone
  15. 15.💾 What number does this code show?
    let coins = 6;
    coins = coins - 3;
    coins = coins + 2;
    show(coins);
  16. 16.💾 What number does this code show?
    let lives = 6;
    lives = lives - 5;
    lives = lives + 3;
    show(lives);
  17. 17.💾 pop() takes off the last item. What does this code show?
    let friends = ["Aman", "Riya", "Kabir", "Meera", "Arjun"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Kabir (b) Meera (c) Aman (d) Riya
  18. 18.💾 Where should the app save a shared to-do list: on the phone or in the cloud? (a) on the phone (b) in the cloud
  19. 19.True or false: a class leaderboard fits saving in the cloud. (a) False (b) True
  20. 20.💾 What is a variable? (a) a picture (b) a phone setting (c) a named box for a value (d) a type of screen
  21. 21.Which of these fits saving in the cloud? (a) a shared to-do list (b) the sound on/off setting (c) notes to read offline (d) a draft you are typing
  22. 22.💾 pop() takes off the last item. What does this code show?
    let friends = ["Arjun", "Riya", "Kabir", "Zoya", "Aman"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Arjun (b) Kabir (c) Zoya (d) Riya
  23. 23.💾 What number does this code show?
    let notes = ["Science", "Art", "Maths"];
    notes.push("Music");
    show(notes.length);
  24. 24.💾 pop() takes off the last item. What does this code show?
    let friends = ["Riya", "Arjun", "Kabir"];
    friends.pop();
    show(friends[friends.length - 1]);     (a) Riya (b) Kabir (c) Arjun
  25. 25.💾 What does this code show? (Positions start at 0.)
    let notes = ["Hindi", "Science", "Music"];
    show(notes[1]);     (a) Science (b) Music (c) Hindi
  26. 26.True or false: chat messages to friends fits saving on the phone. (a) True (b) False
  27. 27.💾 What does this code show? (Positions start at 0.)
    let friends = ["Aman", "Riya", "Kabir"];
    show(friends[0]);     (a) Aman (b) Kabir (c) Riya
  28. 28.💾 Where should the app save your last game level: on the phone or in the cloud? (a) on the phone (b) in the cloud
  29. 29.💾 What does this code show? (Positions start at 0.)
    let songs = ["Ocean", "Sunrise", "Monsoon"];
    show(songs[1]);     (a) Ocean (b) Monsoon (c) Sunrise
  30. 30.True or false: the sound on/off setting fits saving on the phone. (a) True (b) False
  31. 31.💾 In most code, the first item of a list is at position ___. (a) 2 (b) 10 (c) 0 (d) 1
  32. 32.💾 pop() takes off the last item. What does this code show?
    let notes = ["Hindi", "Sports", "Art", "Maths"];
    notes.pop();
    show(notes[notes.length - 1]);     (a) Maths (b) Sports (c) Art (d) Hindi
  33. 33.💾 What number does this code show?
    let songs = ["Rain", "Ocean", "Sunrise"];
    songs.push("Monsoon");
    show(songs.length);
  34. 34.💾 Saving data in the cloud lets you ___. (a) skip the internet (b) shrink the app (c) never need a password (d) use it on any device
  35. 35.💾 What does this code show? (Positions start at 0.)
    let songs = ["Monsoon", "Ocean", "Rain"];
    show(songs[0]);     (a) Rain (b) Monsoon (c) Ocean
  36. 36.Which of these fits saving in the cloud? (a) your last game level (b) a draft you are typing (c) the sound on/off setting (d) photos on two devices
  37. 37.💾 What does this code show? (Positions start at 0.)
    let songs = ["Kites", "Monsoon", "Stars", "Rain"];
    show(songs[3]);     (a) Monsoon (b) Kites (c) Stars (d) Rain
  38. 38.💾 What does this code show? (Positions start at 0.)
    let friends = ["Riya", "Aman", "Arjun", "Meera"];
    show(friends[2]);     (a) Aman (b) Riya (c) Meera (d) Arjun
  39. 39.💾 Where should the app save the sound on/off setting: on the phone or in the cloud? (a) in the cloud (b) on the phone
  40. 40.💾 pop() takes off the last item. What does this code show?
    let songs = ["Stars", "Kites", "Monsoon", "Rain", "Sunrise"];
    songs.pop();
    show(songs[songs.length - 1]);     (a) Stars (b) Kites (c) Monsoon (d) Rain

Answer key

  1. Hindi
  2. Music
  3. Sports
  4. Monsoon
  5. data saved on the phone
  6. True
  7. 5
  8. 3
  9. in the cloud
  10. notes to read offline
  11. in the cloud
  12. 3
  13. a list
  14. in the cloud
  15. 5
  16. 4
  17. Meera
  18. in the cloud
  19. True
  20. a named box for a value
  21. a shared to-do list
  22. Zoya
  23. 4
  24. Arjun
  25. Science
  26. False
  27. Aman
  28. on the phone
  29. Sunrise
  30. True
  31. 0
  32. Art
  33. 4
  34. use it on any device
  35. Monsoon
  36. photos on two devices
  37. Rain
  38. Arjun
  39. on the phone
  40. Rain

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